FIG. 1 (a) is a transmission electron microscope (TEM) photograph of a Cheil nanocomposite resin and FIG. 1 (b) is also a TEM photograph of a Cheil nanocomposite resin
Cheil Industries Inc (Gumi-si, KR) inventors Kee Hae Kwon, Il Jin Kim, Rang Hyung Moon, Jae Bum Park and Seong Ho Kong disclose a thermoplastic nanocomposite resin composition that can be used in products requiring scratch resistance, such as electrical and electronic appliances, interior and exterior materials for automobiles and office equipment in U.S. Patent Application 20090298991. The thermoplastic nanocomposite resin composition allows dispersion of the nanoparticles at a nano level, thereby reducing the content of inorganic filler as compared to a conventional dispersion, and has very excellent scratch resistance while maintaining the formability of a thermoplastic resin.
The Cheil thermoplastic nanocomposite resin composition exhibits improved scratch resistance without deterioration in the inherent physical properties of the resin such as formability, impact resistance and heat resistance. Cheil further provides a thermoplastic nanocomposite resin composition in which the content of inorganic filler can be reduced as compared to conventional dispersions of inorganic filler. As a result, the thermoplastic nanocomposite resin composition can have reduced specific gravity.
The thermoplastic nanocomposite resin composition can be molded for use in housings of electrical and electronic appliances such as television sets, audio sets, washing machines, cassette players, MP3 players, telephones, video consoles, computers, printers, and the like. The thermoplastic nanocomposite resin composition is molded for use as interior and exterior materials for automobiles such as automobile dashboards, instrument panels, door panels, quarter panels, and wheel covers.
Organic surface modified metal (oxide) nanoparticles are prepared by adding 13% by weight of aminopropyl trimethoxysilane into 87% by weight of a colloidal silica sol with a nanoparticle surface area of 150 m2/g and a pH of 1 to 4 and organically modifying the surfaces of particles through a sol-gel reaction.
The metal (oxide) nanoparticles can be substantially uniformly dispersed in the thermoplastic resin matrix using only extrusion. It is currently believed that nanoparticles are substantially uniformly dispersed into a thermoplastic resin matrix during an extrusion/injection molding process through hybrid bonding (physical and chemical adsorption) of the organic surface modified colloidal metal (oxide) nanoparticles and the thermoplastic resin. This in turn is believed to contribute to the improved scratch resistance and protection against surface damage exhibited by molded articles produced using the thermoplastic nanocomposite resin composition of the invention.
In order to overcome these problems, a hard coating method has been widely used to improve scratch resistance of a resin surface by doping a surface of a finally molded resin with an organic-inorganic hybrid material and then curing the organic-inorganic hybrid material using heat or ultraviolet radiation. However, the hard coating method has disadvantages such as long process times, increased costs and environmental problems resulting from the required additional coating process.
Therefore, as a result of such environmental and cost problems, demand for non-coated resins capable of exhibiting scratch resistance without a hard coating has increased.
The metal (oxide) nanoparticles can be substantially uniformly dispersed in the thermoplastic resin matrix using only extrusion. It is currently believed that nanoparticles are substantially uniformly dispersed into a thermoplastic resin matrix during an extrusion/injection molding process through hybrid bonding (physical and chemical adsorption) of the organic surface modified colloidal metal (oxide) nanoparticles and the thermoplastic resin. This in turn is believed to contribute to the improved scratch resistance and protection against surface damage exhibited by molded articles produced using the thermoplastic nanocomposite resin composition of the invention.
Acrylonitrile-butadiene-styrene terpolymer resin is widely used in various articles such as housings for electrical and electronic appliances, interior and exterior materials for automobiles, and office equipment since the acrylonitrile-butadiene-styrene terpolymer resin can have excellent impact resistance, chemical resistance and formability and superior mechanical properties. However, the butadiene-based rubber used to improve impact resistance of the resin can also substantially lower scratch resistance of the resin. As a result, molded articles formed of such resins can easily be scratched during transportation or use, which can damage the external appearance of the articles.
In order to overcome these problems, a hard coating method has been widely used to improve scratch resistance of a resin surface by doping a surface of a finally molded resin with an organic-inorganic hybrid material and then curing the organic-inorganic hybrid material using heat or ultraviolet radiation. However, the hard coating method has disadvantages such as long process times, increased costs and environmental problems resulting from the required additional coating process.
Therefore, as a result of such environmental and cost problems, demand for non-coated resins capable of exhibiting scratch resistance without a hard coating has increased.
